#include <cstdio>
#include <cstdlib>
#include <cstring>
const int maxn = 100000;
int last, cur,next[maxn];
char s[maxn];

int main()
{
	while(scanf("%s",s+1) == 1){
		int n = strlen(s+1);
		last = cur = 0;
		next[0] = 0;

		for(int i = 1;i <= n;i++){
			char ch = s[i];
			if(ch == '[')	cur = 0;
			else if(ch == ']')	cur = last;
			else {
				next[i] = next[cur];
				next[cur] = i;
				if(cur == last)	last = i;
				cur = i;
			}
		}

		for(int i = next[0]; i != 0; i = next[i]){
			printf("%c",s[i]);
		}
		printf("\n");
	}

	return 0;
}





	/*char ch = s[i];
			if(ch = '[') cur = 0;
			else if (ch = ']') cur = last;
			else {
				next[i] = next[cur];
				next[cur] = i;
				if(cur == last) last = i;
				cur = i;
			}*/
